XLII REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



The Lake Trout (Salvelinus namaycush). 



The eggs of this species were taken at North ville from October 15 to 

 November 20. An account of their distribution appears under the dis- 

 cussion of the Michigan Stations. 



A notable circumstance in the distribution of this species was a de- 

 posit, on December 16, 1887, of 500 two-year-olds in a lake in Alpena 

 County, Michigan. The eggs, for the greater part, were taken in small 

 numbers, very few fish being stripped at a time. This prolonged the 

 spawning season to a greater length than in any preceding season. 



90,000 eggs of the lake trout were received at Cold Spring Harbor, 

 December 28, 1887, from Northville. The fry were planted in New York 

 lakes. 



The fry in the troughs were fed on the bellies of soft clams (Mya 

 arenaria) and they all thrived on this food. The same material has 

 proved suitable for the lake trout in the two attempts made to rear 

 them. When the fry were large enough to eat coarser food they re- 

 ceived boiled mussels (Mytilus edulis) chopped fine. In former years 

 lake trout were kept until the middle of the summer, when they would 

 gradually grow less in numbers, and by October would all be gone. 



The lake trout is kept in rearing ponds at the Wytheville Station. 

 At the close of the fiscal year ending June 30, 1888, work was in prog- 

 ress upon a new station at Duluth, Minnesota, for the propagation of 

 this species. 



The Shad (Clupea sapidissima). ♦ 



One of the principal stations for hatching shad is at Fort Washing- 

 ton, Maryland, and details are given in the account of this station. 

 An important departure was effected in the successful operation during 

 1888 of the automatic hatching jars with their tops off. 



During forty-one days 81,177,000 eggs were taken. From the second 

 week of April to June 2, 70,249,000 of these were shipped to Washing- 

 ton from Fort Washington. 



At Fort Washington about two-fifths of the shad eggs were obtained 

 from gill nets and three-fifths from seines. 



Only 8 per cent, of the eggs taken at Fort Washington were gathered 

 between midnight and noon in 1888 ; in 1887, 14 per cent., the average 

 of the two seasons being 11 per cent. In 1887, at Fort Washington, 

 the proportion of male to female shad was nearly 3 to 1. In 1888, it 

 was about 2 to 1. The shrinkage from air exposure in shipping shad 

 eggs from Fort Washington to Washington, in 1888, was about 10 per 

 cent. In the season of 1888 the hatchery at Battery Island, near Havre 

 de Grace, Maryland, was equipped with 386 automatic hatching jars 

 and the iise of cones was discontinued. 7,000,000 shad eggs were taken 

 in one night, prior to May 1, at Havre de Grace. 



A supplementary station was established at Havre de Grace, with a 

 capacity of 10,000,000 eggs at one time. The total production of eggs 

 up to June 4 was 105,315,000. 



